AC/DC battery converter for V2G vehicles

• Main Author: Li, Sishi.
• Other Authors: Wang Peng
• Format: Theses and Dissertations
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/55310
• Institution: Nanyang Technological University

Due to energy crisis and environmental pollution, renewable power conversion systems are connected in distribution systems as distributed generations. Compared to larger grid generation, distributed generation is low pollution, high energy efficiency, flexible installation location and over short transmission distances. Electric vehicles are better than traditional vehicles in terms of clean, energy-saving and environmentally friendly aspects. The EV station is proposed to provide power to micro grid. The main objective of the dissertation is to investigate V2G (vehicle to grid) technique in micro grid. To overcome the gap between battery voltage and AC grid, the AC/DC bidirectional converter and DC/DC bidirectional converter have been designed. In charging mode, the electric vehicle should be controlled to realize the step charging, and the AC/DC converter should be used to keep the de bus voltage constant. In the discharging mode, the DC/DC converter is adopted to keep the de bus voltage constant and AC/DC converter focus on the value of active power and reactive power to transfer. Several simulations have been done to simulate V2G system by MATLAB, e.g., simulation of battery model to realize battery step charging, simulation of rectifier model to realize power flow direction control, simulation of one-charger V2G system both in charging and discharging mode and simulation of multi-chargers V2G system both in charging and discharging mode. For multi-chargers, the chargers being put into operation simultaneously or at different times should be taken into consideration. The simulation results show that the V2G system could provide power to micro grid. The simulation results under different situation show how a V2G system could operate better. The hardware operation schematics and the functions of the main components on the boards have been studied. Even though the design consideration and software simulation have been accomplished, there are still some other works to do in the future. The main parts in the future work are to run the simulations on the hardware and collect data, a check whether the data meets the requirement.